Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(Aforetime) before the battle of Tabuk (they sought to cause sedition) they sought to cause you evil things (and raised difficulties for you) right and left (till the Truth came) until the believers became many (and the decree of Allah) the religion of Allah: Islam (was made manifest, though they were loth) of it.
Indeed, they sought to stir up sedition, against you, already before, when you first came to Medina, and scrutinised your affairs, that is, they thought long and hard how to plot against you and invalidate your religion, until the truth, the [victorious] help, came, and God’s command, His religion, prevailed, stood mighty, they still being averse, to it [His religion], entering it superficially.
(Verily, they had plotted sedition before, and had upset matters for you,) `For a long time,' Allah says, hypocrites thought and plotted against you and your Companions, as well as, failing and attempting to extinguish your religion.' This occurred soon after the Prophet migrated to Al-Madinah, when pagan Arabs joined force and the Jews and hypocrites of Al-Madinah waged war against the Messenger. When Allah gave victory to the Prophet in Badr and raised high his word, `Abdullah bin Ubayy and his fellows said, "This (Islam) is a matter that has prevailed.'' They embraced Islam outwardly, and whenever Allah elevated Islam and its people in might, hypocrites increased in rage and disappointment,
(until the truth (victory) came and the decree of Allah became manifest though they hated it.)
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
Allah held them back for He did not like that they should join Jihad unwillingly without any sincere intention for it. As they had no mind to make sacrifices to exalt the cause of Islam, and, therefore, would have taken part in it. half-heartedly to escape the taunts of the Muslims or to create mischief, this would have resulted in a greater evil, as has been stated explicitly in the next verse (48).